Retrievable well packer



sept. 3, 1968 H. L. MCGILL RETRIEVABLE WELL PACKER Filed Dec. SO, 1966 5Sheets-Sheet l Hon/afa M65/ INVENTOR.

sept. 3, 1968 H. MCG|| 3,399,729

RETRIEVABLE WELL PACKER ATTORNEY Sept. 3, 1968 H, McG|LL i 3,399,729

VRETRIEVABLE WELL PACKER Filed Dec. 30, 1966 3 Sheets-Sheet 5 Howe/'d LMc 6'/// INVENTOR WMM/KWWL? ATTORNE Y United States Patent() 3,399,729RETRIEVABLE WELL PACKE Howard L. McGill, Houston, Tex., assignortoSchlumberger Technology Corporation, Houston, Tex., a corporation ofTexas Filed Dec. 30, 1966, Ser. No. 606,272 16 Claims. (Cl. 166-120)ABSTRACT F THE DISCLOSURE A well packer apparatus wherein the expandinganchor comprises two distinct means, one being mechanically actuated andadapted to anchor the packer against movement in one direction and theother being hydraulically` operated and adapted to anchor the packeragainst movement in the other direction. Structure is provided forpositively preventing premature operation of either of the anchor means.Additionally, an integral bypass device is included for selectivepressure equalization as well as a pressure balancing system.

This invention relates generally to subsurface well tools and moreparticularly to a new and improved retrievable well packer apparatusadapted to be positioned in a well conduit and anchored againstlongitudinal movement therein.

A typical retrievable well packerwhich can be used for performingpressure operations in a well generally includes normally retractedslips and packing which can be selectively expanded for respectivelyanchoring against downward movement in a well casing and packing off theannulus between the well casing and a tubing string on which the wellpacker is lowered into the well. A uid bypass can be provided which isnormally open to facilitate rapid movement of the packer through thewell fluids during lowering and retrieving and which can be utilized toequalize uid pressures on the packer after a pressure operation iscompleted. With the slips and packing expanded and the bypass closed,iluids can be displaced under pressure through the tubing string andwell packer and into the well casing below the packer for performingvarious pressure operations common in the art, such as squeezecementing, acidizing or hydraulic fracturing.

The pressures developed during such operations act as forces on thepacker tending to shift it upwardly within the casing. Since upwardmovement can unset the packer, it is common practice to provide anauxiliary anchoring mechanism which functions to prevent upwardmovement. Typically, such auxiliary anchoring mechanisms includenormally retracted gripping pistons or buttons which are actuated intogripping engagement with the Well conduit in response to fluid pressuresdeveloped during the abovementioned pressure operation.

During rapid descent into a well, fluid pressure surges can be createdwhich cause premature operation of the gripping pistons. The grippingpistons are moved outwardly by the pressure surges and dragged along thewell conduit wall untiltheir. gripping portions are dulled or otherwisedamaged to an extent that they will not function properly when thepacker is set.

An object of the present invention is to provide a new and improved wellpacker apparatus which can be set in a well conduit and anchored againstmovement in either longitudinal direction.

Another object of the present invention is to provide a new and improvedwell lpacker apparatus of the type described which is more positive inoperation than has heretofore been known in the art in preventingpremature actuation of hydraulically operated anchors.

Another object of the present invention is to provide ice a new andimproved'well packer apparatus of the type described having auxiliaryanchors for preventing upward movement under pressure, the anchors beingstructurally arranged in a manner to positively prevent their operationas the well packer is shifted in either longitudinal direction in afluid filled well bore. Moreover, the well packer of the presentinvention can have an integral fluid bypass arrangement which will notbe inadvertently opened during a pressure operation.

Yet another object of the present invention is to provide a new andimproved well packer apparatus which is effective, simple and reliablein operation,

These and other objects are obtained in accordance with the presentinvention by providing an apparatus including an anchor body havingexpansible packing means mounted for sealing engagement with the wellconduit and a mandrel movable in said anchor body. A first passagewaybetween the mandrel and the anchor body is provided for bypassing wellfluids through the packing means and a valve means is provided forselectively closing the first passageway, the valve means being actuatedby movement of the mandrel. Normally retracted gripping members on theanchor body are shiftable outwardly of the anchor body into grippingengagement with the well conduit and a hydraulic member is movable inresponse to uid pressure for shifting the girpping members outwardly. Asecond passageway in communication with the rst passageway is providedto enable fluid pressure to act on the hydraulic member. Means on themandrel is engageable with the hydraulic member to prevent movement ofthe hydraulic member, and thus actuation of said gripping member, whenthe bypass valve is in its open condition.

The present invention has other objects and advantages Which will becomemore apparent in connection with the following detailed description. Thenovel features of the present invention being set forth withparticularity in the appended claims, the operation together withfurther objects and advantages thereof, may best be understood by way ofillustration and example of certain embodiments and taken in conjunctionwith the accompanying drawings, in which:

FIGURES 1A and 1B are longitudinal sectional views, with portions inside elevation, of one embodiment of a well packer apparatus inaccordance with the present invention and with parts in retractedpositions for longitudinal movement in a well bore, FIG. 1B forming alower continuation of FIG. 1A;

FIGURES 2A and 2B are views similar to FIGURES lA and 1B except withvarious parts in expanded positions and the well packer set in a wellcasing;

FIGURE 3 is a plan view of a J-slot which can be used in controllingrelative movement of parts of the Well packer;

FIGURE 4 is a longitudinal sectional view, with portions in sideelevation, of another embodiment of an apparatus in accordance with thepresent invention;

FIGURE 5 is a cross section on line 55 of FIGURE 4 and;

FIGURE 6 is a fragmentary cross section on line 6 6 of FIGURE 5.

Referring initially to FIGURE 1, a well packer apparatus 10 which'embodies the principles of the present invention is illustrated withparts thereof in running-in positions. The well packer 10 includes atubular mandrel 11 which is telescopically disposed within an anchorbody 12 for sliding movement therein between the extended and contractedpositions. The mandrel 11 has a central bore 13 and extends throughoutthe full length of the tool. A threaded box portion 14 at the upper endof the mandrel 11 is adapted for connection with a tubing string (notshown) and the lower end of the mandrel has a threaded pin portion 15 towhich a section of pipe or another well tool can be connected. Themandrel bore 13 is arranged to continue the full bore size of the tubingstring to which the mandrel is coupled.

The anchor body 12 has a reduced diameter compression sleeve 17 coupledto its lower end around which a pliant, elastomeric packing means 18 canbe mounted. The upper end of the packing means 18 engages a downwardlyfacing annular shoulder or abutment 19 and the lower end engages theupper face of an annular abutment ring 20 which is slidable on thecompression sleeve 17. The abutment ring 20 is connected to the upperend of a sleeve 21 which extends downwardly to an expander member 22.The packing means 18 can take any conventional form and is shown forpurposes of illustration as comprising a plurality of elastomericpacking rings 23 separated by metallic gauge rings 24, the packing ringsbeing adapted for lateral expansion upon compression thereof. Theexpander member 22 and sleeve 21 can be co-rotatively secured to thecompression sleeve 17 by means of coengaging splines 25 or the like. Theexpander member 22 has downwardly and inwardly inclined outer surfaces26 thereon which are engageable with mating inner surfaces 27 on aplurality of slip members 28 in a manner whereby downward movement ofthe expander member relative to the slip members will cause outwardshifting of the slip members.

Movably mounted at the lower end portion of the mandrel 11 is a tubularcage member 30. A J-slot 31 typically can be formed in the outerperiphery of the mandrel 11 for cooperation with a lug 32 extendinginwardly from the cage member 30, the .I-slot and lug functioning tocontrol relative movement between the cage member and the mandrel. TheJ-slot 31, shown in developed view in FIGURE 3, can have a long verticalsegment 33 and a relatively short vertical segment 35, the segments 33and 35 being connected by a tapered segment 34. The lug 32 engages inthe short segment 35 when the parts are in a running-in position asshown in FIG- URES 1A and 1B so that the cage member 30 cannot movesubstantially relative to the mandrel 11 in either longitudinaldirection.

The cage member has a plurality of circumferentially spaced, radiallydirected recesses 37 in its outer periphery, each of the recessesreceiving a typical drag block 38. The drag blocks are urged outwardlyby springs 39 for frictional engagement with a well casing wall andfunction to retard movement of the cage member 20 within the wellconduit in a conventional manner. Outward movement of the drag blocks 38can be limited by annular bands 40 and 41 which are arranged to engagetangs 42 and 43, respectively on each drag block 38.

The slip elements 28 can be movably connected on the upper end of thecage member 30 by T shaped extensions 44 which slidably engage incomplementary recesses 45 in the cage member 30. Moreover, aconventional dovetail flange and groove connection 46 between each slipelement 28 and the expander member 22 may be provided so that relativemovement between the slip elements and the expander member will effectlateral movement of the slip elements to and from a well casing wall.Wickers or teeth 47 on the peripheral surfaces of each slip element 28are formed to face downwardly and are adapted to bite into and grip awell casing to anchor the well packer 10 against downward movementtherein.

An intermediate portion 50 of the mandrel 11 is spaced laterally awayfrom the inner surface of the compression sleeve 17 to provide anannular fluid bypass passageway 51. The passageway 51 extends from aplurality of side ports 52 in the expander member 22 to a plurality ofbypass ports 53 which extend through the wall of the anchor body 12above the packing means 18. An internal annular recess 54 in the anchorbody 12 adjacent to the upper end of the bypass passageway 51 isarranged to receive a seal ring '55. The seal ring 55, in turn, has aninternal groove 56 in which a suitable bypass seal element 57 islocated. For selectively closing the bypass passageway 51, the mandrel11 has an enlarged diameter section 58 to provide a valve head which isnormally located above the seal element 57 and above the bypass ports 53when the mandrel is in its extended position as shown in FIGURE 1A. Inthis relative position of parts, the bypass passageway 51 is open forbypassing well fluids through the packing means 18 as the well tool isshifted longitudinally in a well conduit. When the mandrel 11 is movedto a lower or contracted position relative to the anchor body 12, thevalve head 58 is moved adjacent to the bypass seal element 57 to blockfluid ow through the bypass ports 53 and thus prevent any uid movementthrough the bypass passageway 51. Although the seal element 57 has beenshown positioned on the anchor body 12, it will be appreciated that theseal element 57 could be alternatively arranged around the valve head 58and adapted to seal against an inner seal surface on the anchor bodywhen the mandrel is moved downwardly.

The portion of the anchor body 12 above the bypass ports 53 is providedwith a plurality of circumferentially spaced, generally rectangularshaped openings 60 each of which receives a holding slip 61. Eachholding slip 61 has an inner inclined surface extending downward andinwardly toward the mandrel 11 and has upwardly facing Wickers or teeth62 on its outer surface. Each slip 61 can be slidably connected to theanchor body 12 by an extension 63 which is received within an inclinedgroove 64 so that the holding slips can be shifted laterally betweeninner or retracted positions as shown in FIGURE 1A and outer oranchoring positions where the teeth 62 can grip a well conduit wall toprevent upward movement therein.

A hydraulically operated slip expander member 65 is provided forshifting the holding slips 61 between their retracted and extendedpositions. The expander member 65 is generally tubular in form and isarranged for longitudinal movement within an internal annular recess orchamber 66 formed in the anchor body 12. The chamber 66 is closed off atits upper end by an inwardly extending ange and a seal ring 76 sealinglyengages the outer surface of the mandrel 11. The expander member 65 hasouter inclined surfaces 67 at a lower portion extending downward andinwardly toward the mandrel 11. The inclined surfaces 67 arecomplementary in shape and engageable with inclined surfaces 68 on theholding slips 61 so that downward movement of the expander member 65will effect outward extension of the slips. Each slip 61 can also have aconventional dovetail flange and groove connection 69 to the expandermember 65 so that upward movement will effect retraction of the slips 61away from a conduit wall.

The bore of the expander member 65 is sized for sliding reception on themandrel 11 and a suitable seal element such as an O-ring 71 sealsbetween the inner periphery of the expander member and the outer surfaceof the mandrel. Another seal element 72 seals between the outerperiphery of the expander member 65 and the wall surface of the chamber66. The cross-sectional area A between the two seal rings 71 and 72defines a differential area piston on which fluid pressure can act. Aninternal, elongated annular recess 73 is formed intermediate the ends ofthe expander member 65 and a shoulder or flange 74 on the mandrel 11extends outwardly into the recess 73. The mandrel shoulder 74 isarranged to engage a downwardly facing shoulder 75 on the expandermember 65 when the mandrel is in its upper or extended position as shownin FIGURE 1A. In this manner, the engaged shoulders 74 and 75 canfunction positively to prevent any downward movement of the expandermember 65 relative to the holding slips 61. Accordingly, the holdingslips 61 are positively prevented from being shifted outwardly as longas the parts of the well packer are in their relative positions forlongitudinal movement in a well bore.

The expander member 65 is adapted to be hydraulically operated, whendesired, to eiect outward shifting of the holding slips 61 intoanchoring engagement with a well casing. For hydraulic operation, apressure communicating passageway 77 is formed in the mandrel 11 toextend from a location below the bypass valve head 58 to later-al ports78 and 79 which communicate the passageway 77 with the expander memberrecess 73 and with the anchor body chamber 66 above the expander member65. When the bypass valve head 58 is engaged with the bypass sealelement 57 by movement of the mandrel 11 to its lower or contractedposition relative to the anchor body 12, the lower end 80 of thepressure communicating passageway 77 is disposed in a position below thebypass seal element 57. Accordingly, the fluid pressure which exists inthe bypass pasageway 51 is communicated to the pressure communicatingpassageway 77 and into the body chamber 66 to act on the upper side ofthe expander member 65. The lower side of the expander member 65 is incommunication' with the well annulus above the packing element 18 viathe anchor body recesses 60. Therefore, a pressure difference betweenfluids in the bypass passageway 51 and in the annulus above the packingelement 18 can act on the dilerential area A as a force tending to movethe hydraulic expander member 65 vertically relative to the holding slip61.

An upper internal annular recess in the anchor body 12 forms a chamber82 which receives a balance piston 83, the balance piston beingintegrally formed on the mandrel 11. A suitable seal element 84 ispositioned to seal between the balance piston 83 and the w-all of thechamber 82. Several side ports 85 in the anchor body 12 enable annuluspressures above the packing element 18 to `act on the lower face of thebalance piston 83. The pressure communicating passageway 77 is arrangedto extend upwardly to a port means 86 above the piston 83 to enablefluid pressure in the bypass passageway 51 to act on the upper face ofthe balance piston 83. Additionally, an annular floating piston member87 is received at the upper portion of the chamber 82 for slidingmovement between an upper position where the oating piston engages theinwardly extending ange 88 at the upper end of the chamber 82, and alower position where the balance piston abuts against a stop shoulder 89formed on the mandrel 11. Inner and outer seal elements 93 and 94prevent fluid leakage past the floating piston 87. Annulus pressuresoutside of the anchor body 12 can act through side ports 90 on the upperface of ythe floating piston 87 while uid pressures in the bypasspassageway 51, being reected in the pressure communicating passageway77, can act on the lower face of the floating piston member 87.Accordingly, any pressure differential which may be developed can act onthe area B of the balance piston 83 and the area C of the floatingpiston 87 for purposes which will be subsequently described.

In operation, the parts of the well packer are assembled as shown inFIGURES lA and 1B and the mandrel 11 coupled to a tubing string forlowering into a well casing. During lowering, the cage member 30 isretained in its lower position on the mandrel 11 by engagement of thelug 32 within the short vertical segment 35 of the I-slot 31. The dragblocks 38 can slide along in frictional engagement with a well casingwall and the lower slips 28 are maintained in retracted -positionsbecause the cage member 30 cannot move relatively upwardly toward theexpander member 22. The packing rings 23 are unexpanded and the valvehead 58 on the mandrel 11 is positioned above the bypass seal element 57so that well fluids can enter the bypass passageway 51 through the lowerside ports 52 and exit through the upper bypass ports 53.

The hydraulic expander member 65 is held in its upper or inactiveposition by the mandrel shoulder 74 and therefore cannot move downwardlyin a manner to actuate the holding slips 61 outwardly. Accordingly, itwill be appreciated that although the holding slips 61 can be eventuallyhydraulically operated, they are posiltively prevented from beingprematurely operated by tluid pressure surges which can be developedwithin the it/ell packer during rapid descent into a fluid filled wellore.

At setting depth, the well packer is halted and a small upward movementcoupled with right hand rotation of the mandrel 11 will position the lug32 for entry into the long vertical J-slot segment 33 to permitsubstantial downward movement of the mandrel 11 relative to the cagemember 30 for setting the well packer. During downward movement of themandrel 11, the slips 28 and the cage member 30 are held againstdownward movement by the drag blocks 38. Downward movement of themandrel 11 will advance the expander member 22 downward relative to theslips 28 to shift them outwardly into gripping engagement with the wellcasing P as shown in FIGURE 2B. Further mandrel movement will move thevalve head 58 adjacent to the bypass seal element 57 to close the bypasspassageway to fluid flow and to engage the mandrel box portion 14 withthe upper flange 88 on the anchor body 12.

Inasmuch as the abutment sleeve 21 is supported against further downwardmovement by the slips 28, the weight of the tubing string can be appliedto the mandrel 11 and transmitted through the anchor body 12 to theupper end of the packing element 18. As weight is applied, the upperabutment 19 is advanced toward the lower abutment ring 20` to compressand expand the packing rings 23 outwardly into sealing engagement withthe surrounding well casing wall. The weight of the tubing string can bemaintained on the well packer to maintain its set condition. It will benoted that when the well packer is set and the bypass ports 53 closed oiby the valve head 58, the lower of the pressure communicating passageway77 is disposed below the bypass seal element 57 so that whatever fluidpressures may exist within the mandrel bore 13 and in the annulus belowthe expanded packing element 18 are communicated through the bypasspassageway 51, the pressure communciating passageway 77 and to the upperside of the hydraulic expander member 65 via the ports 78 and 79.Moreover, the pressure is also communicated to a location between thebalance piston 83 and the oating piston 87 via the ports 86. Aspreviously mentioned, whatever uid pressures may exist in the wellannulus above the expanded packing element 18 can act on the lower sideof the hydraulic expander member 65 through the holding slip recesses60, on the lower face of the balance piston 83 through the side ports85, and on the upper face of the oating piston 87 via the upper sideports 90.

A pressure operation such as squeeze cementing, acidizing, or hydraulicfracturing can now be performed in an interval below the packer 10. If,as is usually the case, tubing pressure should exceed annulus pressure,the pressure difference will act as a force attempting to shift the wellpacker 10 upwardly within the casing P as well as attempting to move themandrel 11 upwardly. However, the high tubing pressure is also acting onthe upper side of the hydraulic expander member 65, while the lowerannulus pressure is acting on the lower side of the hydraulic expandermember. Accordingly, the pressure difference acts on the area A as adownward force which moves the hydraulic expander member 65 downwardlyto shift the holding slips 61 into 4gripping engagement with the wellcasing, thereby preventing any upward movement of the well packer 10.Moreover, the higher tubing pressure is communicated into the balancechamber 82 to act downwardly on the upper face of the mandrel. balancepiston 83, while lower annulus pressures are acting on the lower face onthe balance piston. Accordingly, the pressure difference can act acrossthe area B as a downward force tending to counterbalance the upwardforce on the mandrel 11 due to high tubing pressure, therebysubstantially minimizing the net upward force on the mandrel andpreventing any upward shifting of the mandrel 11 during a pressureoperation. The pressure differential is also acting upwardly on the areaC of the floating piston 87 but the floating piston can merely shiftupwardly into engagement with the anchor body flange '88. Since theanchor body 12 is anchored against upward movement by the holding slips61, the upward force on the floating piston 87 is of no consequence.

Should annulus pressure exceed tubing pressure, for example, where fluidis lifted within the tubing by swab- ,bing to test the success of anacidizing operation, the

higher annulus pressure acts downwardly on the well packer in aconventional manner to set the packing element 18 and the lower slips 28even more tightly within the well casing P. However, the higher annuluspressure will tend to lift the hydraulic expander member 65 upwardlywithin the anchor body 12 since the lower tubing pressure is acting onthe upper side of the hydraulic expander member 65. Under thisinfluence, the hydraulic expander member 65 can move upwardly until itsupper end surface 91 engages a downwardly facing shoulder 92 on theanchor body 12. This movement will retract the holding slips 61 and canoccur without the hydraulic member 65 engaging the mandrel stop shoulder74. Since the lower tubing pressure is now acting on the upper 4face ofthe balance piston 83 and the higher annulus pressure is acting on thelower face thereof, there is an upward force on the area B on thebalance piston 83. However, the pressure difference is now actingdownwardly on the floating piston 87 which can move downwardly -toengage the stop shoulder 89 on the mandrel 11. The effective pressureareas B and C of the balance piston and oating piston respectively canbe made substantially the same so that force on the mandrel 11 due topressure acting on the pistons is counterbalanced. Accordingly, themandrel 11 will not be moved upwardly to inadvertently open the bypassports 53.

To release the well packer 10 for retrieval to the surface it is onlynecessary to remove the tubing weight from the mandrel 11 and lift themandrel upwardly. If the holding slips 61 are not already retracted byhigher annulus pressure as previously described, upward movement of themandrel 11 will engage the mandrel shoulder 74 with the hydraulicexpander member 65 and thus shift it upwardly to retract the holdingslips 61. Also, upward movement of the mandrel 11 will position thevalve head 58 above the bypass seal element 57 to open the bypass ports53 and permit equalization of any existing pressure differentials acrossparts of this packer. As compressive force is removed from the packingrings 23, they will inherently retract and eventually the lower expandermember 65 will be moved upwardly relative to the lower slip elements 28to cause their release and retraction. When sufllcient upward mandrelmovement has occurred, the cage member will occupy its initial lowerposition relative to the mandrel 11 and the lug 32 will again engage inthe slot segment to re-jay and lock the packer parts in retractedpositions for longitudinal movement in the casing P.

An alternative embodiment of an apparatus which ernbodies the principlesof the present invention is shown in FIGURE 4. Only the upper portion ofthe apparatus is shown for convenience of illustration and it will beappreciated that the lower portion can embody structural elementssimilar to those shown in FIGURE 1B or their equivalents. A mandrel 111is telescopically disposed for movement in anchor body 112 between anextended position, as shown, and a. contracted position where a boxportion 114 on the mandrel 111 engages an inwardly extending flange 116on the anchor body. The mandrel 111 has a central bore 113 extendingthroughout its length which can continue the full bore of a tubingstring (not shown) to which the box portion 114 can be connected.

The anchor body 112 has a reduced diameter compression sleeve 117threadedly coupled to its lower end', the compression sleeve having anelastomeric packing element 118 mounted around its periphery with itsupper end engaging a downwardly facing shoulder or abutment 119 on theanchor body 112. The inner periphery of the compression sleeve 117 islaterally spaced from the outer periphery of the mandrel 111 to providean annular bypass passageway 120 which extends upwardly to several sideports 121 in communication with the well annulus above the packingelement 11S. A bypass seal element 122 is disposed adjacent the upperend portion of the bypass passageway 120 and can be positioned within aninternal annular groove formed in a seal ring 124 which is, in turn,located with an internal annular recess in the anchor body 112. Asuitable seal element 126 can be positioned adjacent to the seal ring124 to prevent any fluid leakage past the seal ring.

An annular valve head 128 is formed on the mandrel 111 by an enlargeddiameter portion thereof. The valve head 128 is normally positionedabove the bypass seal element 122 when the mandrel 111 is in itsextended position so that fluids can flow freely through the bypasspassageway 120 and the side ports 121. When the mandrel 111 is moveddownwardly relative to the anchor body 112, the outer peripheral surfaceof the valve head 128 can sealingly engage the bypass seal element 122to block fluid flow from the bypass passageway 120 to the well annulusvia the side ports 121.

The anchor body 112 has upper and lower annular chambers 130 and 131,respectively, formed therein and separated by an annular, inwardlyextending flange 132. The upper annular flange 116 extends inwardly toclose the upper end of the upper chamber 130 and a seal element 134sealingly engages the outer surface of the mandrel 111. The upperchamber 130 is opened to the exterior of the anchor body 112 by aplurality of circumferentially spaced, generally rectangular shapedopenings 135 and each of the openings receive a holding member in theform of a slip element 136. The slip elements 136 are each movablewithin a respective opening between a retracted position, as shown, andan extended position. Each slip element 136 can be slidably connected tothe anchor body 112 by a T shaped extension 137 at its lower end whichengages in a mating inclined groove 138 in the inwardly extending flange132. Moreover, each slip element 136 has inner inclined surfaces 139which extend downwardly and inwardly toward the mandrel 111 and hasupwardly facing wickers or teeth 140 on its outer periphery which areadapted, when the slip element is extended, to grip a well casing wall.

For actuating the holding slips 136 between retracted and extendedpositions, a hydraulic member is provided which is arranged forreciprocating movement within the upper chamber 130. The hydraulicmember 130 is generally tubular in form and has a bore therethroughwhich is sized for sliding reception on the mandrel 111. An inner sealelement 146 seals between the inner surface of the hydraulic member andthe outer surface of the mandrel 111 while an outer seal element 147seals between the outer periphery of the hydraulic member and the wallsurface of the chamber 130. The crosssectional area A between the twoseal elements 146 and 147 defines a differential area piston on whichfluid pressure can act.

The lower end portion of the hydraulic member 145 can have a .pluralityof longitudinally extending pockets 150, each of which receives awedge-shaped expander insert 151. The expander inserts 151 can berigidly but removably connected to the hydraulic member 145 by suitablefasteners such as threaded studs 152. Each insert can have an inwardlyextending lip 153 which engages in a recess 154 to further secure theinserts for longitudinal movement with the hydraulic member 145. Theouter surface 155 of each expander insert 151 is formed to inclinedownwardly and inwardly toward the mandrel 111 and is complementary inshape to the inner inclined surfaces 139 on the holding slips 136. Eachslip 136 is arranged to engage a respective insert 151 in a mannerwhereby downward movement of the hydraulic member 145 will effectoutward movement of the slips. Each holding slip 136 can further besldably connected to a respective expander insert 151 by a conventionaldovetail ange and groove arrangement 156 so that upward movement of thehydraulic member '145 will elect inward retraction of the slips.

To enable uid pressure to act on the hydraulic member 145, a pressurecommunicating passageway 160' can be formed to extend along the mandrel111 from an opening 161 below the valve head 128 to an opening 162 whichis in communication with the upper chamber 130 above the hydraulicmember 145. Thus it will be appreciated that whatever uid pressuresexist in the bypass passageway 120 are reflected in the upper chamber130 to act on the upper side of the hydraulic member 145 whether thevalve head 128 is in its open or closed position. Also, whatever fluidpressure may exist in the well annulus above the packing element 118 iscommunicated through the anchor body openings 135 to act on the lowerside of the hydraulic member 145. Accordingly, whenever the iiuidpressure in the bypass passageway 120' exceeds the annulus pressure, thepressure difference acts on the area A' as a force in a downwarddirection tending to move the hydraulic member 145 downwardly and toexpand the holding slips 136.

In order to prevent premature expansion of the holding slips 136 whenthe mandrel 111 is in its extended position for lowering or retrievingin a well bore, the mandrel is provided with several outwardly extendinglugs or shoulders 164 as shown in FIGURES 5 and 6 which can becircumferentially offset relative to the slips 136. The shoulders 164are sldably received in grooves 165 which extend longitudinally in thehydraulic member 145, the upper end of each groove 165 defining adownwardly facing shoulder 166 against which the upper face of arespect-ive mandrel lug 164 can engage when the mandrel 111 is in itsextended position. Accordingly, the hydraulic member 145 is positivelyretained in an upper or inactive position and cannot move downwardly toshift the holding slips 136 outwardly. It will be appreciated that thisstructural arrangement prevents any possibility of premature actuationof holding slips 136 when the parts of the well packer are in relativepositions for longitudinal movement in a well. However, when the wellpacker is set and the mandrel 111 is in its contracted position withinthe anchor body 112, the mandrel lugs 164 are moved downwardly away fromthe groove shoulders 166 a suiiicient distance to permit freelongitudinal movement of the hydraulic member 145 as it functions toactuate the holding slips 136.

, The pressure differential necessary to operate the hydraulic member145 and thus the holding slips 136 is derived from the high tubingpressures normally developed during a pressure operation. The hightubing pressure is communicated from below the well packer upwardlythrough the closed bypass passageway 120, through the pressurecommunicating passageway 160, the passageway opening 162 and into theupper chamber 130 to act on the upper side of the hydraulic member 145.As the tubing pressure exceeds the annulus pressure which is acting onthe lower side of the hydraulic member 145, downward force is developedto reciprocate the hydraulic member 145 downwardly and thereby shift theholding slips 136 outwardly to anchor the Well packer 110 against upwardmovement in response to high pressure from below.

The higher uid pressure within the mandrel 111 also acts on the mandrelin an upward direction and tends to turely. Accordingly, a balancingsystem is included in accordance with the present invention andcomprises a piston 168 which can be integrally formed on the mandrel 111and arranged for reciprocating motion within the lower chamber 131. Aseal element 169 in a suitable groove around the outer periphery of thepiston 168 engages the wall surface of the chamber 131 to prevent fluidleakage past the piston. An annular floating piston member 171 is alsopositioned within the chamber 131 above the balance piston 168 and innerand outer seals 172 and 173 prevent uid leakage past the lioatingpiston. It will be appreciated that the iloating piston 171 is free tomove lonigtudinally within the chamber 131 between limits defined by thelower face 174 of the ange 132 and the upper face of the balance piston168. The chamber space located between the balance piston 168 and thefloating piston 171 is placed in communication with the pressurecommunicating passageway 160 by a lateral port means 176.

The balancing system operates in the following manner. When there existshigh tubing pressure, the pressure is communicated through the bypasspassageway 120, past the valve head 128 via the pressure communicatingpassageway 160 and into the chamber space between the two piston members168 and 171. The pressures in theannulus above the packer arecommunicated to the upper face of the floating piston 171 through theanchor body openings 135, and to the lower face of the balance piston168 through the bypass ports 121. The pressure difference will act onthe balance piston area B as a downward force on the mandrel 111 tendingto counterbalance the upward force on the mandrel due to high pressurefrom below. Accordingly, the bypass valve head 128 will not be lifted toan open position by the high tubing pressure. Under these conditions,the oating piston member 171 can merely move upwardly until Iit engagesthe anchor body ilange 132. Forces on the floating piston 171 cannotcause upward movement of the anchor body 112 because it is anchoredagainst upward movement by holding slips 136.

Moreover, should annulus pressure exceed tubing pressure, the pressuredifference will act upwardly on the hydraulic member to shift itupwardly until its upper end surface 178 engages the lower surface 179of the upper anchor body ange 116. This movement will retract theholding slips 136 and can occur without transmitting any force directlyto the mandrel 111. Since the upper end of the anchor body 112 isengaging the box portion 114 on the mandrel 111, the anchor body 112cannot move upwardly relative to the mandrel 111 responsive to highannulus pressures. Also, the directions are reversed in which pressureforces are acting on the balance piston 168 and the ioating piston 171.That is to say, should annulus pressure exceed tubing pressure, thepressure difference acts on the area B as an upward force, and on thearea C as a downward force. Under these influences, the oating piston171 can move downwardly to engage the balance piston 168 and the areas Band C can be made the same so that the net force is zero due topressures acting on the oating and balance pistons.

The various parts of the apparatus shown in FIG- URE 4 can be operatedto retracted positions for retrieval from the well by upward movement ofthe mandrel 111 in the same manner as described relative to theapparatus shown in FIGURES lA and 1B. Upward movement of the mandrel 111will open the bypass passageway 129 to equalize pressures and permitretraction of the packing element 118 as well as engaging the mandrellugs 164 with the hydraulic member shoulders 166 to retain the hydraulicmember 145 in its upper or inactive position. The well packer 110 canthen be retrieved from the well bore or moved to another settingposition.

A new and improved well packer has been disclosed which can be anchoredin a well conduit against movement in either longitudinal direction. Thewell packer has an integral bypass and pressure equalizing means as wellas a pressure balancing system. The well packer is structurally arrangedto prevent premature operation during lowering or retrieving.

Since certain changes or modifications may be made in the disclosedembodiments of the present invention without departing from theinventive concepts involved, it is intended that the appended claimscover all such changes or modifications falling within the true spiritand scope of this invention.

I claim:

1. A well packer for use in a well bore comprising: a body member; amandrel movable in said body member and adapted for connection to arunning-in string, said mandrel having a bore; packing means on saidbody member adapted for sealing off said body member in a well bore;slip means movable between retracted and expanded positions foranchoring said body member in a well conduit against substantialmovement in either direction, at least one of said slip means disposedon said body member on one side of said packing means; hydraulic meansfor actuating said one slip means; passage means extending from saidhydraulic means to the other side of said packing means along said bodymember said mandrel and externally of said bore to enable fiuid pressureon said other side to act on said hydraulic means; and means on saidmandrel engageable with said hydraulic means for releasably holding saidslip means in a retracted position.

2. The well packer of claim 1 further including chamber means betweensaid mandrel and said body member; balancing means on said mandrel andmovable in said chamber means; and means to enable said fluid pressureto act on said balancing means.

3. A well tool comprising: an anchor body having expansible packingmeans mounted thereon for sealing engagement with a well conduit; amandrel movable in said anchor body; a first passageway between saidmandrel and anchor body for bypassing well fluids through said packingmeans; passageway closing means actuated by movement of said mandrel forselectively closing said first passageway; a second passageway incommunication with said first passageway; normally retracted grippingmembers on said anchor body shiftable outwardly of said anchor body forgripping a well conduit; hydraulic means movable in response to pressurein said first and second passageways for shifting said gripping membersoutwardly; and means on said mandrel engageable with said hydraulicmeans for normally preventing movement of said hydraulic means toactuate said gripping members when said passageway closing means isopen.

4. The well packer of claim 3 including piston means on said mandrelsubject to fiuid pressure to said first and second -passageways whensaid passageway closing means is closed for exerting a force on saidmandrel in a direction to maintain said first passageway closing meansclosed.

5. A well tool comprising: an anchor body; a mandrel telescopicallyarranged in said anchor body; expansible packing means on said anchorbody adapted for lateral expansion to pack off a well conduit; a bypasspassageway between said packing means and said mandrel and extendingalong said mandrel between locations above and below said packing means;valve means actuated by telescoping movement of said mandrel andarranged to close said bypass passageway adjacentan end portion thereof;holding means on said anchor body shiftable outwardly thereof forgripping a well conduit to prevent movement in one longitudinaldirection; hydraulic means movable between said mandrel and said anchorbody for shifting sai-d holding means outwardly; pressure communicatingmeans for enabling fluid pressure in said bypass passageway to act onsaid hydraulic means; and means on said mandrel engageable with saidhydraulic means for selectively preventing operation of said hydraulicmeans, thereby selectively preventing operation of said holding means.

6. The well tool of claim 5 further including cylinder means in saidanchor body; balance means on said mandrel and sealingly engaging saidcylinder means; and means to enable fluid pressure in said bypasspassageway to act on said balance means.

7. The well tool of claim 5 wherein said hydraulic means has inclinedsurfaces slidably engageable with inclined surfaces on said holdingmeans for shifting said holding means outwardly.

8. The well tool of claim 7 further including coengageable means on saidinclined surfaces for shifting said holding means inwardly to retractedpositions.

9. The well tool of claim 5 further including first cylinder means insaid anchor body, and wherein said hydraulic means includes seal meansslidably and sealingly engaging said first cylinder means.

10. The well tool of claim 9 further including second cylinder means insaid anchor body; balancing means on said mandrel and sealingly engagingsaid second cylinder means; and means to enable fluid pressure in saidbypass passageway to act on said balance means.

11. A well packer comprising: body means having expansible packing meansmounted thereon for sealing engagement with a well conduit; a mandreladapted for connection to a pipe string and movable in said anchor bodybetween first and second positions; a bypass passageway between saidmandrel and body means and extending along said mandrel betweenlocations above and below said packing means; bypass passageway closingmeans actuated by movement of said mandrel for closing said bypasspassageway in one of said positions, said bypass passageway being openin the other of said positions; another passageway in communication withsaid lbypass passageway when said mandrel is in at least one of saidpositions; normally retracted gripping members on said body means andshiftable outwardly thereof for gripping a well conduit; hydraulic meansactuated in response to pressure in said other passageway for shiftingsaid gripping members outwardly; and means including a shoulder on saidmandrel engageable with said hydraulic means for holding said hydraulicmeans against movement when said bypass passageway is open to positivelyprevent outward shifting of said gripping members.

12. A well packer apparatus comprising: a body; a mandrel telescopicallydisposed in said body for movement between extended and contractedpositions; normally retracted slips and packing means lfor respectivelyanchoring in a well conduit and packing off well conduit, said slipmeans -being arranged to prevent movement of said apparatus in onelongitudinal direction; a bypass passageway between said packing meansand said mandrel; valve means operable when said mandrel is in saidcontracted position for closing said bypass passageway; normallyretracted gripping members on said Ibody for anchoring said apparatusagainst movement in the opposite direction; hydraulic means foractuating said gripping members into anchoring engagement with a wellconduit; means for enabling tiuid pressure in said bypass passageway,when closed, to act on said hydraulic means; and means on said mandrelengageable with said hydrulic means when said mandrel is in its extendedposition for preventing operation of said hydraulic means.

13. A well packer comprising: an anchor body; a sleeve coupled to thelower end portion of said anchor tbody; elastomeric packing meansmounted around said sleeve and adapted for expansion to pack ofi a wellbore; a mandrel adapted for connection to a tubing string and extendingconcentrically through said anchor body and sleeve, said m-andrel beingarranged for telescoping movement therein between extended andcontracted relative positions; Ia bypass passageway between said sleeveand said mandrel and extending between locations above and below saidpacking means; bypass closing means operated by movement of said mandrelto said contracted position for selectively closing said bypasspassageway; slip members on said anchor body and shiftable outwardlythereof for anchoring against movement in a well casing; hydraulic meansfor shifting said slip member outwardly, said hydraulic means beingmovable along said mandrel and said anchor Ibody; means to enable iluidpressure to act on said hydraulic means including a pressurecommunicating passageway extending between locations below said bypassclosing means and yabove said hydraulic means; yand means engageablewith said hydraulic member when said mandrel is in said extendedposition for preventing movement of said hydraulic means, thereby `toprevent outward shifting of said slip members.

14. The well packer of claim 13 further including chamber means betweensaid anchor body and said mandrel; a balance piston coupled to saidmandrel and movable in said chamber means; and means to enable iluidpressure in said pressure communicating passageway to act on saidbalance piston for exerting a balancing force on said mandrel when saidhydraulic member is actuating said slip members.

15. The well packer of claim 14 further including a iloating pistonmember movable in said chamber means relative to Iboth said mandrel andsaid anchor body; and means to enable uid pressure to act on saidfloating piston member for balancing force on said balance piston whensaid hydraulic member is not actuating said slip members.

16. A we-ll packer comprising: an anchor body; a mandrel movable in saidanchor body between exten-ded and contracted positions; expansiblepacking means mounted on said lanchor body and arranged to pack oi awell bore; means operable when said mandrel is in said contractedposition for expanding said packing means; holding means on said anchorbody and shiftable between extended and retracted positions foranchoring against movement in one longitudinal direction; hydraulicmeans between said anchor body and mandrel and movable relative to bothsaid anchor body and said mandrel for shifting said holding meansbetween extended and retracted positions; means for enabling fluidpressure to act on said hydraulic means including a normally open bypasspassageway between said mandrel and said anchor |body 'and extendingbetween locations above and below said packing means; valve meansoperable when said mandrel is in said contracted position for closingoff said bypass passageway, said enabling means being in communicationwith said bypass passageway when closed; and means engageable with saidbydraulic means when said mandrel is extended for holding said'hydraulic means in an inactive position so that sai-d hydraulic meanscannot function to shift said holding means.

References Cited UNITED STATES PATENTS 2,878,877 3/1959 Baker 166-120 X3,020,959 2/ 1962 Nutter 166-134 3,233,675 2/1966 Tamplen et al. 166-134X 3,283,819 11/1966 Tausch 166-120 3,283,824 11/1966 Hoiman et al.166-120 X 3,338,308 8/1967 Elliston et al. 166-120 DAVID H. BROWN,Primary Examiner.

